# #21b09a

A color — vivid. Deterministic analysis from BrandSweets (no inference).

## Values

- Hex: `#21b09a`
- RGB: rgb(33, 176, 154)
- HSL: hsl(171, 68%, 41%)
- OKLCH: oklch(0.681 0.118 179)
- Relative luminance: 0.3371
- Nearest named color: Billiard (#00af9f, Δ 1.026) — https://brandsweets.com/colors/billiard
- Moods: vivid
- Page: https://brandsweets.com/colors/21b09a

## Tints & shades

- Tints (toward white): #26c9b1, #31d8bf, #4bddc7, #65e2cf, #7ee7d7, #94ebde, #aeefe6, #c7f4ee, #ddf8f4, #f6fdfc
- Shades (toward black): #1e9f8b, #1c9280, #188171, #156f62, #136357, #105148, #0c4038, #092f29, #07221e, #03110f

## Harmonies

- Complementary: #b02137
- Analogous: #21b053, #217eb0
- Triadic: #9a21b0, #b09a21
- Split-complementary: #b0217e, #b05321
- Tetradic: #5321b0, #b02137, #7eb021

## Colors that go with #21b09a

Named partners (harmony on the OKLCH wheel, co-occurrence in curated palettes and brand systems, and the neutrals that carry it), best first:

- **Charcoal** #36454f [role, pool] — Charcoal is the text near-black for #21b09a: softer than #000 and cool enough to feel like part of the same palette. Seen in: N26 (https://brandsweets.com/colors/brands/n26-com), Lagoon (https://brandsweets.com/palettes/vivid#lagoon), Mint Modern (https://brandsweets.com/palettes/modern#mint-modern), Coastal (https://brandsweets.com/palettes/cool#coastal). — https://brandsweets.com/colors/charcoal
- **Hot Pink** #ff69b4 [harmony, pool: complementary] — Hot Pink sits directly opposite #21b09a on the wheel — the strongest contrast one hue can give another, so use it small: a button, a link colour, one highlight. Seen in: Terminal (https://brandsweets.com/palettes/technical#terminal). — https://brandsweets.com/colors/hotpink
- **Cornflower Blue** #6495ed [pool] — Designers have shipped Cornflower Blue with #21b09a: 4 real palettes, including Canva's brand system and Spotify's brand system, as the supporting colour. Seen in: Canva (https://brandsweets.com/colors/brands/canva-com), Spotify (https://brandsweets.com/colors/brands/spotify), Terminal (https://brandsweets.com/palettes/technical#terminal), Arctic (https://brandsweets.com/palettes/clean#arctic). — https://brandsweets.com/colors/cornflowerblue
- **Midnight Blue** #191970 [pool] — 7 real palettes, including Fintech Trust and Ford's brand system put Midnight Blue beside #21b09a, as the text colour against it. Seen in: Fintech Trust (https://brandsweets.com/palettes/cool#fintech-trust), Ford (https://brandsweets.com/colors/brands/ford-com), Tide Pool (https://brandsweets.com/palettes/cool#tide-pool), Confluent (https://brandsweets.com/colors/brands/confluent-io). — https://brandsweets.com/colors/midnightblue
- **Mustard Yellow** #ffdb58 [pool] — 4 real palettes, including Diner and Lido put Mustard Yellow beside #21b09a, as the accent. Seen in: Diner (https://brandsweets.com/palettes/vivid#diner), Lido (https://brandsweets.com/palettes/vivid#lido), Crayon Box (https://brandsweets.com/palettes/playful#crayon-box), Fresh Juice (https://brandsweets.com/palettes/playful#fresh-juice). — https://brandsweets.com/colors/mustard
- **Royal Blue** #4169e1 [pool] — Royal Blue is paired with #21b09a in 6 real palettes, including Khan Academy's brand system and Brilliant's brand system, as the accent. Seen in: Khan Academy (https://brandsweets.com/colors/brands/khanacademy-org), Brilliant (https://brandsweets.com/colors/brands/brilliant-org), Confluent (https://brandsweets.com/colors/brands/confluent-io), Console Light (https://brandsweets.com/palettes/technical#console-light). — https://brandsweets.com/colors/royalblue
- **Taupe** #483c32 [pool] — Taupe is paired with #21b09a in 12 real palettes, including Resort and Undergrowth, as the text colour against it. Seen in: Resort (https://brandsweets.com/palettes/light#resort), Undergrowth (https://brandsweets.com/palettes/dark#undergrowth), Chime (https://brandsweets.com/colors/brands/chime-com), Crayon Box (https://brandsweets.com/palettes/playful#crayon-box). — https://brandsweets.com/colors/taupe
- **Tomato** #ff6347 [harmony, pool: split] — Tomato is a split-complement of #21b09a: nearly opposite, so it still pops against it, without the vibrating edge of a true complement. Seen in: Lido (https://brandsweets.com/palettes/vivid#lido), Crayon Box (https://brandsweets.com/palettes/playful#crayon-box), Fresh Juice (https://brandsweets.com/palettes/playful#fresh-juice). — https://brandsweets.com/colors/tomato

## Contrast (WCAG 2.x, as text)

- On white (#ffffff): 2.71:1 — AA fail, AA-large fail, AAA fail. Fix: AA: text → #198575 (4.51:1); AA: background → #333333 (4.66:1); AAA: text → #136357 (7.12:1); AAA: background → #0f0f0f (7.07:1)
- On black (#000000): 7.74:1 — AA pass, AA-large pass, AAA pass

## Palette tool

Open this color locked as the lead with four explored companions: https://brandsweets.com/palettes/new/21b09a-a2bebd-d459a7-1f292d-e9f1ec?lock=0&style=vibrant
(Humans lock/regenerate in the tool; the URL is the state — read `lock=` back to see what they kept.)

## Connect an agent

Point any MCP client at the BrandSweets colors endpoint for the same engine:

- Endpoint: https://mcp.brandsweets.com/colors/mcp
- Tools: `analyze_color` (e.g. `analyze_color({ color: "#21b09a" })`), `check_contrast` (with fixes), `generate_palette` (explore around locks), `suggest_palette` (mood/industry → curated-first), `list_palettes`.